package com.dp.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @author KT917
 * @date 2022/11/24
 */
public class SimpleRedisLock implements ILock {

    private String name;
    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true)+"-";

    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT=new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public SimpleRedisLock(String name) {
        this.name = name;
    }

    /**
     * @param timeoutSec  锁持有的过期时间 超时自动释放
     * @return
     */
    @Override
    public boolean tryLock(long timeoutSec) {
        String threadId = Thread.currentThread().getId()+ID_PREFIX;
        //获取锁
        Boolean success = stringRedisTemplate.opsForValue().
                setIfAbsent(KEY_PREFIX + name, threadId ,
                        timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }

//    @Override
//    public void unlock() {
//        //获取线程标识
//        String threadId = Thread.currentThread().getId()+ID_PREFIX;
//        //获取锁中标识
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        if (threadId.equals(id)){
//            //释放锁
//            stringRedisTemplate.delete(KEY_PREFIX + name);
//        }
//    }

        @Override
    public void unlock() {
       //调用lua脚本
            stringRedisTemplate.execute(UNLOCK_SCRIPT,
                    Collections.singletonList(KEY_PREFIX + name),
                    Thread.currentThread().getId()+ID_PREFIX);
    }



}
